Credit advice- trying to buy a house & due in June

Hi! My husband and I are trying to qualify for a home- we make about $85000/ yr and he has great credit (780). I don’t, however- it’s sitting at 650 which isn’t awful by apparently not good enough to get a decent loan despite rates being great right now. I have two credit cards I’ve been chipping away at, plus two student loans I have also been paying down. Paid off my car earlier this year 🎉 (but still $45000 in debt all together) I should mention I make more than him currently.

We already pay $1450 a month in rent, and have a down payment ready. I feel like we should have been able to qualify but have only had one mortgage company run our credit so far- they wouldn’t loan based on that info.

Does anyone had advice for me? I have one CC I could pay down to owe only 30% of the balance and would like to refinance the student loans but I am worried about taking out a loan before we apply for a mortgage.

My in laws offered to co- sign, I don’t think it would be any trouble on that relationship. Is this the way we should go?